A presidential commission said yesterday that several unions influenced by organized crime had infiltrated the US marketplace and that federal efforts to crack down on the racketeering had been hampered by the Labor Department's "undeniable susceptibility" to political pressure from the unions.

In addition, in a report that was presented to President Reagan at the White House, the commision questioned whether a Justice Department investigation into the Teamsters union president, Jackie Presser, had been delayed because of Presser's political support for Reagan in 1980 and 1984. Declaring that organized crime figures seek to cultivate influence among politicians, the President's Commission on Organized Crime stated it "is convinced that the impact of such (political) contacts can lead to an erosion of public confidence and dampen the desire to end racketeering."

Spokesmen for both the Departments of Labor and Justice refused comment on the substance of the commission's report. In addition, John K. Russell, a Justice Department spokesman, said he could make no comment about the commission's statements on Presser because the matter involved a criminal investigation.

The Justice Department began its investigation last summer after allegations that agents of the Federal Bureau of Investigation knew that Presser had no-show employees on his Teamsters' payroll but they did nothing because Presser was providing them with information on other investigations.

The commission, which was formed by Reagan in 1982, also said in its report that organized crime's influence in unions and businesses will not be eliminated unless the president develops a full-scale national strategy to attack the problem.

"There has never been a coherent federal strategy to attack organized crime's corruption of business institutions and labor organizations," said the commission's chairman, Judge Irving R. Kaufman of the US Court of Appeals for the 2d Circuit. "There has never been a consistent and substantial commitment of investigative and prosecutorial resources."

Four major unions have had histories of being controlled or influenced by organized crime, the report said. They are the International Longshoremen's Association, the Hotel Employees and Restaurant Employees International Union, the International Brotherhood of Teamsters and the Laborers International Union of North America.

None of the unions' international offices in Washington or New York City could be reached for comment.

As for the allegation of political influence, the report said that former Labor Department investigators have charged that former Labor Secretary Raymond Donovan had exercised "prompt intervention" when they opened several investigations of powerful unions. Donovan resigned last year after being indicted for fraud in New York.

"Such contacts (by Donovan) indicated, either implicitly or explicitly, that it was unwise to disrupt certain established political relationships," the report stated. "One of the key obstacles to more vigorous oversight of labor-management racketeering by the Labor Department is the department's undeniable susceptibility to political pressure" from the leadership of the unions.

The number of unions believed to have connections to organized crime is a small fraction of the 70,000 labor organizations in the United States, the report stressed. But, "influence of these key local unions allowed organized crime to dominate the international unions and to acquire a foothold in the marketplace."

The commission held back from releasing the chapters of its report that details organized crime's influence over these and other unions because it did not want to influence a criminal case against several major mob figures now being tried in New York City, said Arthur P. Brill Jr., commission spokesman. Those chapters, along with another on organized crime's influence on several legitimate businesses in the construction and meat distribution industries, will be made public after the trial.

Brill said none of the businesses or union locals examined by the commission were located in Greater Boston. However, some unions in the Boston area are influenced by "Boston's Irish gangs," even though to a smaller degree than in years past, the report said.

A longtime federal investigator in Boston corroborated the commission's assessment of organized crime's involvement in local unions. "I don't think they (the gangs) are in it for any grand scheme." Some members of the Winter Hill gang in Somerville are members of the Teamsters, the investigator said, ''but it's just to pick up a paycheck or maybe a questionable disability check. I don't think there's any major conspiracy going on here."